Apparatus for processing yarn



April 10, 1962 c. e. EVANS APPARATUS FOR PROCESSING YARN 4 Sheets-Sheet 1 Filed April 11, 1957 INVENTOR. CYRIL G. EVANS BY \fi ATTORNEY April 1952 c. G. EVANS 3,028,654

APPARATUS F OR PROCESSING YARN Filed April.1l, 1957 4 $heetsSheet 2 INVENTOR. %p|| G. EVANS BY 7 ATTORNEY April 1962 c. G. EVANS 3,028,654

APPARATUS FOR PROCESSING YARN Filed April 11, 1957 4 SheetS-Sheet 3 F 9. 3 INVENTOR.

CYRIL G. EVANS ATTORNEY April 0, 1962 c. G. EVANS 3,028,654

APPARATUS FOR PROCESSING YARN Filed April 11, 1957 4 Sheets-Sheet 4 INVENTOR. CYRIL G. EVANS ATTORNEY Uit States Patented Apr. 10, 19.62

3,928,554 APPARATUS FOR PROCESSING YARN Cyril G. Evans, Clemson, S.C., assignor to Deering Miliihen Research Corporation, Pendieton, S.C., a corporation of Delaware Filed Apr. 11, 1957, Scr. No. 652,153 8 Claims. (Cl. 28-1) This invention relates to improved apparatus for the manufacture of crinkled or coiled yarns having an elastic nature and, more particularly, the invention relates to improved apparatus for elasticizing yarns by passing the same through a sharply angular path under tension. This application is a continuation-in-part of application Serial No. 630,325 filed December 24, 1956.

An early type of apparatus for elasticizing yarns by passing the same through a sharply angular path under tension is disclosed in U.S. Patent 2,919,534. In this early type of apparatus the yarn is heated by passing the same into surface contact with a stationary heater strip or plate and the tension in the yarn passing about a blade edge is controlled by means of a mechanical tension regulator. This early type of apparatus had certain disadvantages for use with some types of yarns and in U.S. Patent 2,992,358 there is disclosed an improved form of apparatus designed to overcome certain of these disadvantages. In that apparatus a rotary heater is employed to heat the yarn and the tension. in the yarn passing about the blade edge is controlled by an overfeed system such that the tension in the yarn passing about the blade edge is determined primarily by its thermal contraction characteristics. While the latter apparatus is an improvement in many respects over earlier types of apparatus, it does not completely overcome the problem of tension control in all instances and introduced several new problems to apparatus employing a rotary heater.

A simple overfeed arrangement, such as employed in the apparatus of U.S. Patent 2,992,358 functions to provide near perfect tension control as long as the yarn being processed is characterized by uniform thermal contraction characteristics, but unfortunately yarns as received from the manufacturer do not have uniform thermal contraction characteristics. This is primarily because in a freshly manufactured pirn or the like of yarn, the yarn near the outside of the package can and does contract to a greater extent than the turns of yarn lying adjacent the spool or core of the package, and this differential contraction results in the yarn having unle-vel thermal contraction characteristics. If yarn from the manufacturers package is processed on apparatus employing a simple overfeed arrangement, the unlevel thermal contraction characteristics of the yarn will result in tension fluctuations as the yarn passes about the blade edge and the changes in yarn tension result in non-uniformity in the processed yarn. This lack of uniformity shows up as streaks or bands when the yarn is formed into hosiery or the like and is, therefore, quite objectionable. Because of this, it has heretofore been necessary to rewind yarn from the manufacturers packages and to allow the rewound yarn to remain for a period of time in the new packages before processing the same on a paratus employing over-feed tension control. This rewinding operation adds appreciably to the total cost of processing the yarn and it is a first object of this invention to provide apparatus, embodying an improved overfeed arrangement, on which yarns can be satisfactorily processed directly from the yarn packages supplied by various yarn manufacturers.

Another problem associated with prior apparatus employing a roll type heater has been that of insulating the heater to hold heat losses to a satisfactory level while at the same time maintaining the surface of the roll at a uniform selected temperature. It is accordingly another object of this invention to provide an improved yarn heater roll and improved means for retaining the yarn engaging surface of said roll at a uniform selected tempe rature with low heat losses.

It has also been a disadvantage of prior apparatus utilizing a roll type heater that there has been provided no completely satisfactory means for holding a blade in operative position adjacent the periphery of the heater roll. In order for uniform yarn to be produced, it is necessary that there be provided blade holding means capable of exactly positioning the blade edge with respect to the heater roll and which permits the blade to readily be removed from and returned to operative position. It is, therefore, still another object of this invention to provide improved blade holding means for use with a rotary yarn heater which permits the apparatus to be readily threaded and which makes possible precise positioning of the blade with respect to the rotary heater.

The above, as well as other objects of the invention, are accomplished by apparatus comprising means to transport a running length of yarn under tension through a linear path about the edge of a blade member, a roll member positioned in the yarn path immediately preceding the point at which the yarn operatively contacts the blade edge, and means to rotate the roll such that it has a peripheral surface speed in excess of the linear rate of movement of the yarn in' surface contact therewith. Preferably, the roll has a construction such that it can be mounted upon a heated shaft and such that the length through the bore of the roll is substantially greater than the face width thereof. The blade member is preferably held by means comprising a support member .pivoted about an axis which extends generally parallel to the axis of the roll and which lies generally opposite 7 from the side of the roll where the blade member is operatively positioned.

One embodiment of the invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a schematic view of apparatus according to this invention showing principal parts in location;

FIGURE 2 is a front elevational view of a portion of the apparatus schematically illustrated in FIGURE 1;

FIGURE 3 is a cross-sectional view taken substantially along the line 3-3 of FIGURE 2 of the drawings;

FIGURE 4 is a front view of a portion of the appara-' tus illustrated in FIGURE 2 with parts shown broken away and in section to illustrate details of construction;

FIGURE 5 is a front view of another portion of the apparatus illustrated in FIGURE 2 with parts broken away and in section.

With reference to the drawings in greater detail and with particular reference to FIGURE 1 of the drawings, the reference numeral 10 generally indicates one of a plurality of conventional supply means for furnishing, in each instance, an end of yarn 11. While a single position apparatus according to this invention can readily be constructed, it is an advantage that the apparatus is Well adapted for mutiple unit construction, and in all but FIGURE 1 of the drawings, portions of two or more positions of a multiple unit apparatus are illustrated. Corresponding parts of the two or more positions are, in most instances, correspondingly numbered except that for clarity prime numerals have been employed.

The yarn supply means it) is here illustrated as comprising a yarn supply'package'lil which may be in the form of a spool, pirn or the like and which, in this instance, may suita-bly be a manufacturers supply package. The package 12 is supported by a spindle 13 extending tom 2. support member 14 which may suitably comprise a portion of a conventional down-twister frame. So that the yarn may readily be withdrawn from package 12 there is provided a guide means 16 with a guide eye 17 positioned on the extended axis of spindle 13 and, if desired, the guide means 16 can be provided with a second eye 18. The second guide eye 18 permits the yarn to be wrapped one or more turns about the portion of the guide 16 extending between the two guide eyes so that the guide can serve as a preliminary yarn tensioning means.

From guide eye 18 the yarn 11, under a tension resulting from it being withdrawn from package 12 and passed through guide 16, is passed through a first eye 19 of a double yarn guide 26 to a duplex yarn advancing means, generally indicated by the reference numeral 22, and it will now be apparent that the reason for tensioning the yarn as it is drawn through guide 16 is to prevent it from slipping upon the yarn engaging surfaces of advancing means 22. From the yarn advancing means 22 the yarn 11 passes to one component portion of a rotary heater system, generally indicated by the reference numeral 24, and about the edge 25 of a blade member 26 to one position of a rotary guide system, generally indicated by the reference numeral 27. From guide system 27 the yarn 11 passes about one component position of an oiling system, generally indicated by the reference numeral 28, through a second guide eye 29 of yarn guide 20 and back to the yarn advancing means 22. From the yarn advancing means 22 the yarn 11 then passes about a guide roll or pulley 30 and through a pigtail guide 31 to a yarn take-up means, generally indicated by the reference numeral 32. The take-up means is here illustrated as comprising a conventional ring and traveler array but may suitably comprise substantially any type of take-up means.

In instances where it is desired to insert twist into the yarn at this time, a ring and traveler array is a particularly advantageous form of take-up means, but in instances where it is desired that no twist be inserted into the yarn,

some other type of take-up means should be employed.

The duplex yarn advancing means 22 comprises a housing 33 which serves as a support for yarn guide 20 and which is secured to a support member 34 by any suitable means, such as bolts 35, only one of which is illustrated. The support member 34 can, and preferably does, constitute that portion of a down-twister frame conventionally employed to support the yarn feed means with which such twisters are conventionally equipped. Extending from one side of the housing 33 is a duplex roll 36 having a first portion 37 and a second portion 38 which may or may not be of the same diameter as portion 37. Generally, it is advantageous for portion 38 to be of smaller diameter than portion 37 for reasons which will subsequently be made apparent. Portion 38 of roll 36 may be formed integrally with portion 37 or, if desired, these two portions of the roll may be separately formed and secured together by any suitable means. Roll 36 is keyed to a first stub shaft 40 which is journaled for rotation through one wall of housing 33, and keyed to a second stub shaft 41, also journaled for rotation through the wall of housing 33, is a second duplex roll 42 having portions 44 and 46 corresponding to portions 37 and 38 of roll 36. Rolls 36 and 42 are driven in timed relationship to each other through shafts 40 and 41 by means of conventional gears, not illustrated, within housing 33, and these gears in turn are driven from a drive shaft 50.

The yarn advancing means 22 is provided with a convention knock-off device, not illustrated, within housing 33 and a start-off control 52 which can be employed to temporarily inactivate the knock-0E device. Start-off control 52 is spring biased so that it normally does not inactivate the knock-off device but when the control is depressed, it inactivates the knock-0E device for such time as pressure on the control is maintained. Normal operation of the knock-off device is effected by two different means, one of which comprises an arm 54 which extends from housing 33 and which carries the yarn guide pulley 30 on its unsupported end. The pulley 30 serves to guide an end of yarn from the yarn advancing means 22 to the take-up means 32, as previously explained, and the tension in the yarn normally serves to move arm 54 against the force of a biasing means, not illustrated, so that the arm 54 is retained out of effective relationship with the knock-off means. In the event of yarn breakage, the arm 54 is moved by the biasing means to effectively engage the knock-off means and to thereby stop the rotation of rolls 36 and 42. The second means acting to operate the knock-off device will be subsequently described.

The duplex yarn advancing means 22 can take any suitable form so long as it provides means for advancing an end of yarn under tension along a linear yarn path at a first selected rate and means to thereafter advance the yarn a second time at a second linear rate. If desired, two distinct yarn advancing means can be employed but a single duplex yarn advancing means is generally preferred for reasons of economy. A suitable yarn advancing means can readily be made from a yarn feed device of the type with which most down-twisters are conventionally equipped and the duplex yarn advancing devices illustrated in the accompanying drawings were made by modification of the yarn feed devices of an Atwood lOB Down-Twister manufactured by Universal Winding Company. The only modifications required in this instance were the modification of yarn guide 20 to provide guide eye 29, lengthening of arm 54 to reposition guide pulley 30, and substitution for the original rolls of duplex rolls 36 and 42.

The rotary heater system 24 comprises a tubular drive shaft 56, preferably formed of a metal, such as copper, having a relatively high heat conductivity (i.e. above about 0.2 calorie per second per square centimeter at C. with a specimen 1 centimeter thick and a 1 C. temperature differential). The drive shaft 56 is journaled for rotation and means, not illustrated, are provided for driving shaft 56 at a fixed rate relative to the rate of rotation of shaft 50 and relative to the rate of rotation of rolls 36 and 42 when the latter are in normal operation. Means are also provided for heating the drive shaft 56 and while the heating means may take any suitable form, it is here illustrated as comprising a plurality of tubular electrical heaters 58 and 58' which are connected in series by means of a conductor 59. The electrical heaters 58 and 58 are positioned internally of tubular shaft 56 in thermal contact therewith so that the shaft 56 is heated by conduction when heaters 58 and 53 are supplied with electrical energy from any suitable source, not illustrated.

Carried by shaft 56 are a plurality of yarn heater rolls 6!) and 66'. Heater rolls 60 and 60 are designed to heat an end of yarn in contact with the peripheral surface thereof and are preferably also made of a metal, such as copper, having a relatively high thermal conductivity so that heat is readily transferred by conduction from shaft 56 to an end of yarn in contact with the peripheral sur face of the roll. When the rolls 60 and 60' are made from copper or the like, it is generally advantageous to provide them with a chromium plated surface to prevent oxidation and corrosion. To assist in heat transfer from shaft 56 to the peripheral faces of rolls 60 and 60 and to reduce heat loss, these rolls are preferably of a tapered configuration so that the length through the bore of the rolls is greater than the face width thereof. Best results are generally achieved when the length through the bore is several, for example 2 to 20, times the face width of the rolls, and when the face width of the rolls is substantially the minimum necessary to accommodate a yarn guide groove such as i indicated by the reference numerals 62 and 62. A peripheral yarn guide groove is necessary when the face width of rolls 60 and 60 is very small to prevent the yarn from possibly wandering 01f the face of the roll and such a groove also serves to eliminate the necessity of guide means positioned in the yarn path between roll 36 and roll 60.

To provide for thermal expansion of shaft 56, this shaft is preferably built with a plurality of expansion joints, one of which is illustrated and indicated in the drawings by the reference numeral 64 (see FIGURE 4). These expansion joints can suitably take the form of a sleeve 65 circumscribing a discontinuity, indicated by the reference numeral 66, in shaft 56. One end of sleeve 65 is firmly secured to the shaft 56 by means of a set screw 67 and the other end of sleeve 65 is keyed to shaft 56 by means of a key 68 which permits longitudinal movement of the portion of shaft 56 on one side of the discontinuity 66 relative to sleeve 65 while insuring that the portions of shaft 56 on either side of the discontinuity 66 rotate as a unit.

Ciroumscribing shaft 56 in spaced relationship therewith and extending between adjacent rolls 60 and 60' is a sleeve member 70, preferably formed from a metal, such as stainless steel, having a relatively low heat conductivity (i.e. below about 0.2 calories per second per square centimeter at 100 C. with a specimen 1 centimeter thick and at 1 C. temperature differential). The sleeve 76 is supported at either end by a pair of annular flanges 72 and 73 extending from the opposite side surfaces of rolls 6i and 60 (FIGURE 4 of the drawings). Preferably the sleeve '76 is firmly secured to one of the flanges 72 or 73 by any suitable means, and, in this instance, sleeve 70 is secured to flange 72 by set screws 74, only one of which is illustrated, while the other end of the sleeve 70 is free to slide upon its supporting flange 73. At least one end of the sleeve 70 must be unsecured to its supporting flange since the sleeve 70 will normally be made from a different material than shaft 56 and will normally be at a'different temperature than shaft 56 so that it will not undergo the same degree of thermal expansion when the heating means is placed in operation.

Circumscribing sleeve 70 in spaced relationship therewith is a metal housing 76 which extends between rolls 6%) and 6t) and preferably covers these rolls up to the edges of the peripheral faces thereof. The housing 76 is preferably formed of two separable parts 77 and 7S and the lower part 78 is provided with a support base 79 which is firmly secured to a support member 80 by any suitable means, such as bolts 81. To provide additional rigidity, a brace 82 extends from between housing 76 and support member 89 to a second support member 84 which in turn is supported by a plurality of uprights 85, only one of which is shown.

Since the expansion joint 64 cannot readily provide complete rigidity, and since shaft 56 is prefer-ably several yards long, it is usually advantageous to provide additional support for the shaft at spaced intervals along its length corresponding to the points at which expansion joints are provided. For this purpose, there is positioned intermediate sleeve 7i) and housing 76 an antifriction hearing, such as ball bearing 86. The inner race of bearing 86 is rigidily secured to sleeve 70 and the outer race is secured in fixed relationship to the inner face of tubular housing 76 to prevent longitudinal movement of sleeve 73 relative to housing 76. This arrangement is advantageous when shaft 56 is provided with a plurality of expansion joints since by virtue of sleeve 70 being secured at one end to a portion of shaft 56 through flange 72, it is impossible for this portion of the shaft 56, even if it lies between two expansion joints, to move longitudinally to thereby throw roll 66, and other rolls, not illustrated, carried by this portion of the shaft, out of proper alignment.

Since sleeve 70 is spaced from shaft 56, it is normally at a lower temperature than shaft 56 and if the sleeve 70 is formed of a material with a relatively low thermal conductivity, the central portions of sleeve 70 will normally be at a much lower temperature than shaft 56.

Therefore, sleeve 79 not only serves to reduce the heat loss from shaft 56, but also serves to provide a relatively cool support for bearing 86 so that it is not necessary for the bearing to be operated at undesirably high temperatures. The housing '76 also serves to reduce the heat loss from shaft 56 and from rolls 6% and 6b, and to further reduce the heat loss, it is generally advantageous to insert insulating material, as illustrated at 88 and 89 in the drawings, in the spaces between sleeve 70 and housing 76 on either side of bearing 86.

It is generally not necessary to provide expansion joints in shaft 56 between each pair of adjacent rolls and when no expansion joint is present between a pair of rolls, it is not necessary to provide additional support for the shaft between these two rolls. To reduce the heat loss, however, it is generally advantageous to provide a sleeve corresponding to sleeve 70 between each pair of adjacent rolls, except that in instances where such a sleeve does not serve as a bearing support, it need not be secured at either end to its supporting flanges. Portions of two such sleeves are illustrated in the drawings and are indicated by the reference numerals 90 and 90. It is also general- 1y advantageous to provide housings, generally corresponding to housing 76, between adjacent rolls even when there is no expansion joint in shaft 56 between the rolls, and portions of two such housings are illustrated in the drawings and indicated by the reference numerals 92 and 92. As with housing 76, housings 92 and 92 are prefer-ably formed of two separable parts 94 and 96 and the lower parts 96 are preferably provided with support bases 98 which are secured to support member 8t) by any suitable means, such as bolts liltl. Although housings 92 and 92' are not necessary to serve as bearing supports, they serve as cover and support for layers of insulating material 162 and 162, which may suitably be formed of rock wool, glass wool or the like, and additionally serve to reduce the heat loss from shaft 56. Housings 92 and 92' also serve another function to be subsequently described but none of these functions places a heavy strain on the housings and they can satisfactorily be made of light gauge sheet metal or'the like.

The rotary guide system 27 comprises a shaft 104, rotatable about an axis generally parallel to the axis of rotation of shaft 56, which carries a plurality of rolls Hi6 and 106, generally aligned with the rolls 6t) and 60', and means, not illustrated, are provided for driving shaft 164 at a fixed rate relative to the rate of rotation of shaft 56. A tubular housing 198 covers the shaft res between rolls 1% and 106 and serves as an outer support for an antifriction bearing member, such as ball bearing 110- (see FIGURE 5 of the drawings) through which shaft 104 is journaled. Housing 103 preferably comprises two separable parts 111 and 112, with part 111 being formed integrally with part 77 of housing 76, and with part 112 being formed integrally with part 78 of housing 7 6. As with shaft 56, it is not necessary that bearing support be provided for shaft 164 between each pair of rolls, but tubular housings 114 and 114', generally corresponding to housing 198, are preferably provided for shaft 104 between roll positions where no bearing support is provided to prevent possible injury to attendant workers.

The oiling system 23 generally comprises a shaft 117, also rotatable about an axis generally parallel to the axis of rotation of shaft 56, which is journaled through a bearing 118 carried by a dependent support member 119 secured to the base of housing 108 by any suitable means, such as screws 12% and 122 (see FIGURE 5 of the drawings). The shaft 117 carries a plurality of oiling rolls 124 and 124, generally aligned with the rolls 106 and 166, which extend into a reservoir trough 126 secured along one edge to the support member 80. The reservoir trough 126' is adapted to be filled with a lubricant to a level sufficient to contact the lower peripheral edge of rolls 124 and 124 and means, not illustrated, are pro vided for rotating shaft 118 so that an end of yarn passing in contact with the surface of rolls 124 and 124' is lubricated by contact therewith.

The blade 26 is held in position by a blade holder assembly, generally indicated by the reference numeral 128. (A second blade holder assembly, in which corresponding parts are designated by primed reference numerals, is partially illustrated in FIGURES 2 and 4 of the drawings and is generally indicated by the reference numeral 128'.) The assembly 128 comprises a first arrn 139 secured to a support member 132 by means of a pivot 134 so that the arm 130 is pivotable, as shown by the dotted lines in FIGURE 2 of the drawings, about an axis which extends generally parallel to the axis of rotation of roll 69 and which is disposed, with respect to roll 60, generally opposite to roll 196. An adjustable stop means, comprising a screw member 136 threaded through a suitable bore in arm 130 with its lower extremity 13S operatively resting upon housing 92 (on housing 76 in the case of screw 136'), is provided so that the angular position of arm 130 with respect to a reference place parallel to the first axis thereof can, within limits, readily be adjusted. A lock nut 140 is provided so that once arm 130 has been properly positioned for satisfactory operation, screw 136 can be locked in position and arm 130 can be pivoted to an inoperative position for purposes of threading the apparatus and can thereafter be readily returned to the exact operative position previously selected.

The unsupported end of arm 130 is bent so that a terminal portion 142 thereof extends generally parallel to the axis of rotation of shaft '56 and the terminal portion 142 is fitted into a suitable bore in a support block 144. Support block 144 is secured in position relative to arm 130 by a set screw 146 which extends through one wall of the block 144 and engages portion 142 of the arm. A bifurcated member 143 having arms 150 and 152 is secured to the top of block 144 by any suitable means such as screws 153, and the arms 150 and 152 are provided, in each instance, with a bore which is aligned with a bore in block 144. A second arm 154 extends through the aligned bores in member 148 and block 144 and is supported by a nut 155 which is positioned between the arms of member 148 and which threadably engages the upper portion of arm 1154. Nut 155 provides means for precisely moving arm 154 along its iongitudinal axis and it will be seen from FIGURE 2 of the drawings that the point of support for arm 154 and the pivot axis of arm 139 lie, when arm 130 is in operative position, in parallel planes extending to opposite sides of the axis of rotation of roll 60. Arm 154 extends downwardly from block 144 and is provided on its lower extremity with a blade securing means of any suitable type, such as spring clamp 156. The spring clamp 156 secures blade member 26 such that its edges 25 is operatively positioned proximate the peripheral surface of roll 60 and such that a line extending from the point at which arm 154 is supported to the blade edge 25 is at an angle to a line extending from the point of support of arm 154 to the pivot axis of arm 130. The projected angle between these two hypothetical lines in a plane parallel to the plane in which arm 13% is pivotable can advantageonsly be within the range of from about 50 to 130 and is preferably approximately a right angle.

By means of screws 136 and nut 155 it is not only possible to precisely adjust the distance between edge 25 and the periphery of roll 60, but it is also possible to adjust, within limits, the position of edge 25 relative to a plane passing through the axes of rotation of shafts 104 and 56. This permits one to vary the included angle between the approaching and departing yarn passing in i an angular path about the edge 25 of blade 26 and also permits adjustment, within limits, of the total angle of wrap of the yarn about roll 60. The latter factor is of importance since roll 60 is operatively rotated at a rate such that its peripheral surface is moving at a speed in excess of the linear rate of movement of the yarn in contact therewith, and the angle through which the yarn is in contact with the peripheral surface of roll 60 determines, other factors being equal, the difference in the tension in the yarn passed to the blade edge 25 and the tension in the yarn passing from yarn advancing means 22 to roll 66.

Extending from arm 139 adjacent pivot 134 is an arm member 160 provided with an eye 162 on its unsupported end. An elongated rod 164, which is connected at its lower end to the knock-off means in yarn advancing means 22, extends upwardly through eye 162 and is provided at its upper end with a nut 166 of larger diameter than the eye 162. When arm is in operative position, rod 164 is lifted by contact of the arm member with nut 166 so that the knock-0E means in yarn advancing means 22 is not thereby activated, but when arm 130 is pivoted to an inoperative position for purposes of threading, rod 164 moves under the force of gravity to activate the knock-off means in advancing means 22. The purpose of this arrangement is to require an operator to place the advancing means 22 in operation by means of start-off control 52 and to return the blade holder 128 to operative position before releas ing control 52 so that the blade holder cannot inadvertently be left in inoperative position with the apparatus running.

In operation, an end of yarn from supply package 12 is threaded through guide 16 and through eye 19 of guide 20 and is wrapped about portions 37 and 44 of rolls 36 and 42 at least a suthcient number of turns to prevent slippage. Generally, about 3 to 10 turns about corresponding portions of rolls 36 and 42 are adequate although a larger number of turns can be employed if desired. With the blade holding means 128 pivoted to an inoperative position, the yarn 11 is then drawn over rolls 60, 106 and 124 and through eye 29 of guide 20. Then yarn end 11 is then wrapped at least a sufiicient number of turns about portions 38 and 46 of rolls 36 and 42 to prevent slippage, is passed over roll 30 through guide 31 and to the take-up means 32. With heater 58 in operation so that the surface temperature of roll 60 is at a proper level and with the various drive means in operation, start-off control 52 is then depressed to place duplex yarn advancing means 22 in operation. It is advantageous to place the duplex advancing means 22 in operation before blade member 26 is lowered into operative position, since with the blade 26 in operative position, the yarn 11 frictionally engages heater roll 60 through a longer are than when blade 26 is removed from operative position, and if one attempts to lower the blade 26 into operative positon before advancing means 22 is placed in operation, the heat resulting from friction between yarn 11 and roll 60 is sometimes sutficient to raise the small segment of the yarn in contact with roll 60 to a temperature above its sticking temperature so that the yarn sticks to roll 60 and is broken. When, however, the yarn is being advanced along its path at a proper rate, blade member 26 can readily be lowered into op erative position without difficulty.

Once the apparatus is in operation, roll 60 serves to reduce the mean tension in the yarn passed to blade edge 25 to a very low value (i.e. at least below about 0.4 gram per denier) and to reduce the numerical magnitude of tension fluctuations in the yarn resulting from the yarn having unlevel thermal contraction characteristics. In other words, if the tension in the yarn moving into contact with edge 25 tends to increase, it results in the yarn being drawn against the periphery of roll 60 with increased force so that the yarn in contact with the periphery of the roll has an increased tendency to move at the same rate as the periphery of the roll. As a result, the numerical value of the tension increase in the yarn between rolls 36 and 60 is much larger than the tension increase in the yarn in the portion of the yarn path immediately preceding the edge 25 or, in other words,

the tension in the yarn passing about the blade edge fluctuates only slightly even with large variations in the ther mal contraction characteristics of the yarn being proo essed.

The roll 1% serves not only as a guide means to force the yarn to follow a proper path about the edge 25 of blade 26, but also serves to cool the yarn and to tension the yarn in the portion of the yarn path between roll 1% and portion 46 of roll 42. Although the tension in the yarn between roll 106 and the portion 46 of roll 42 is not of prime importance, the fact that the yarn is under higher tension in this portion of the yarn path than at the time it passes about the blade 26 provides adequate contact between the yarn and portions 38 and 46 of rolls 36 and 42 with fewer wraps about rolls 36 and 42.

The surface speed of portion 44 of roll 42 and of portion 37 of roll 36 relative to the surface speed of portions 38 and 46 of these two rolls determines the amount that the yarn is allowed to contract in passing about heated roll 64 and is of great importance in determining the degree of elasticity imparted to the yarn being processed. For best results, the difference in the rate at which the yarn is first advanced and the rate at which the yarn is advanced following its contact with the blade edge should be sufiicient to allow the yarn being processed to contract a near maximum possible extent along the face thereof which contacts the edge 25 or, in other words, the rate of overfeed should be substantially the maximum at which the yarn can be transported through the appartus without becoming slack between rolls 6t}- and 166. With any given yarn this can readily be empirically determined, but as a guide, the optimum percent overfeed is about numerically equal to one-half the percent the yarn will contract when heated in a tensionless condition. With most yarns, the optimum percent overfeed is from about 1 to 15% and, for example, it has been found that du Pont nylon type 200 is preferably overfed approximately 7 to 8%, American Erika type 6 nylon (Nylenka) is preferably overfed approximately 10 to 12% and du Pont Dacron polyester yarn is preferably overfed 12 to 15%. The linear rate at which the yarn is processed can be conventional and, for example, may suitably be from 1 to 500 yds. per minute or even higher.

The rate of rotation of rolls 6% and 106 relative to the linear rate of movement of the yarn should theoretically make little difference as long as roll 60 is rotated so that it has a surface speed in excess of the rate of movement of the yarn in contact therewith and roll 106 is rotated such that the surface thereof has a rate of movement less than the speed of the yarn in contact therewith but in actual practice, it has been found that best results are generally obtained when roll 65) is rotated such that its surface is moving approximately 1 to 3% faster than the linear rate of movement of the yarn and roll 106 is rotated such that it has a surface speed about 10 to less than the speed of the yarn in contact with the surface thereof. The rate of rotation of roll 124 is of importance only in determining the amount of lubricant applied to the yarn and will vary depending upon the particular lubricant applied and the purpose for which the processed yarn is to be employed.

Having thus described my invention, what I desire to claim and secure by Letters Patent is:

1. Apparatus for processing a running length of yarn comprising a first yarn unheated advancing means to positively advance an end of yarn at a first selected linear rate, a second unheated yarn advancing means to thereafter positively advance said end of yarn at a second linear rate which is less than the linear rate which said yarn is advanced by said first yarn advancing means, a roll member positioned in the yarn path between said first and second yarn advancing means, means to heat at least a portion of the surface of said roll member so that the temperature of said yarn in contact therewith is elevated, a blade member, positioned between said roll member and said second yarn advancing means, having a sharp edge positioned immediately adjacent the peripheral surface of said roll member, guide means to guide said'end of yarna partial wrap only around the periphcry of said roll member for sliding'frictional contact therewith and immediately thereafter about said sharp edge in an acutely angular manner with said edge positioned at the apex of the angle in the yarn path, means to rotate said roll member such that it has a surface speed in excess of the linear rate at which the yarn is operatively advanced by said first yarn advancing means.

2. Apparatus according to claim 1 including tensioning means comprising a second roll member positioned in the yarn path proximity to the point where said yarn contacts said blade edge, and including means to drive said second roil member such that it has a peripheral speed less than the rate of movement of the yarn in contact therewith.

3. Apparatus for processing a running length of yarn comprising a yarn supply means, a first yarn advancing means to positively advance an end of yarn from said supply means at a first selected linear rate, a second yarn advancing means to thereafter positively advance said end of yarn at a second linear rate, a roll member positioned in the yarn path intermediate said two yarn advancing means, a blade member having a sharp edge positioned adjacent the peripheral surface of said roll member, guide means to guide an end of yarn a partial wrap about the periphery of said roll member and immediately thereafter about said sharp edge in an acutely angular manner with said edge positioned at the apex of the angle in the yarn path, means to rotate said roll member such that it has a surface speed in excess of the linear rate at which the yarn is operatively advanced by said first advancing means, a blade holding means, and means, associated with said blade holding means, for removing said blade member from an operative position to facilitate threading of the apparatus, including a knock-off means to render inoperative said first and second yarn advancing means, and means associated with said blade holding means and said knock-01f means to effect operation of said knock-off means when said blade member is moved to an inoperative position, and a yarn take-up means to collect said yarn subsequent to its being advanced by said second yarn advancing means.

4. Apparatus for processing a running length of yarn comprising a yarn supply means, a first yarn advancing means to positively advance an end of yarn from said supply means at a first selected linear rate, a second yarn advancing means to thereafter positively advance said end of yarn at a second linear rate, a roll member positioned in the yarn path intermediate to said yarn advancing means, means to heat at least a portion of the surface of said roll member so that the temperature of said yarn in contact therewith is elevated, a blade member having a sharp edge positioned adjacent the peripheral surface of said roll member, guide means to guide an end of yarn a partial wrap around the periphery of said roll member and immediately thereafter about said sharp edge in an acutely angular manner with said edge positioned at the apex of the angle in the yarn path, means to rotate said roll member such that it has a surface speed in excess of the linear rate at which the yarn is operatively advanced by said first yarn advancing means, a hollow rotatable shaft carrying said roll member, means to heat said hollow shaft, said roll member having a yarn guide groove circumscribing its periphery, and said roll member being tapered so that the length through the bore of said roll member is substantially greater than the face width thereof, said face width being substantially the minimum required to accommodate said yarn guide groove, and a yarn take-up means to collect said yarn subsequent to its being advanced by said second yarn advancing means.

5. Apparatus according to claim 4 wherein said shaft carries a plurality of roll members, an annular flange extending from the opposed side surfaces of two adjacent roll members, said shaft being provided with an expansion joint intermediate said two adjacent roll members, a sleeve extending between said two adjacent roll members, said sleeve being supported at either end by said flanges, a stationary housing circumscribing said sleeve, a bearing member disposed between said housing and said sleeve to facilitate rotation of said sleeve, and heat insulating material disposed between said sleeve and said housing on either side of said bearing member.

6. Apparatus for processing a running length of yarn comprising in combination a first unheated yarn advancing means to positively advance an end of yarn at a first selected rate, a second unheated yarn advancing means to thereafter positively advance said end of yarn at a second linear rate, first and second rolls positioned in the yarn path intermediate said first and second yarn advancing means such that the yarn operatively engages each of said two rolls through a partial wrap only about each to provide sliding frictional contact therewith, said two rolls being disposed in proximate spaced relationship to each other, a blade member having an edge operatively positioned intermediate said two rolls so that said yarn in passing from said first roll to said second roll passes about said edge in an angular path with said edge disposed at the apex of the angle in the yarn path, means to heat the peripheral surface of said first roll, means to drive said second yarn advancing means such that the rate at which the yarn is advanced thereby is less than the rate at which the yarn is advanced by said first yarn advancing means, whereby the yarn, in a segment of the yarn path immediately preceding the point where said yarn contacts said blade edge, is under only slight tension and undergoes thermal contraction, means to rotate said first roll such that it has a surface speed in excess of the linear rate at which said yarn is operatively advanced by said first advancing means and means to rotate said second roll such that it has a surface speed less than the surface speed of said first roll.

7. Apparatus for processing a running length of yarn comprising in combination a first yarn advancing means to positively advance an end of yarn at a first selected rate, a second yarn advancing means to thereafter ad vance said end of yarn at a second linear rate, first and second rolls positioned in the yarn path intermediate said first and second yarn advancing means such that the yarn operatively engages each of said two rolls through a partial wrap about each, said two rolls being disposed in proximate spaced relationship to each other, a blade member having an edge operatively positioned intermediate said two rolls so that said yarn in passing from said first roll to said second roll passes about said edge in an angular path with said edge disposed at the apex of the angle in the yarn path, means to heat the peripheral surface of said first roll, means to rotate said first roll such that it has a surface speed in excess of the linear rate at which said yarn is operatively advanced by said first advancing means, means to rotate said second roll such that it has a surface speed less than the surface speed of said first roll, blade holding means, and adjusting means, associated with said blade holding means, to vary the position of said blade edge with respect to a plane passing through the axes of said first and second rolls, and to vary the distance said blade edge is removed from the periphery of said first roll.

8. Yarn processing apparatus comprising in combination a first heated roll and a second unheated roll positioned in the yarn path in proximate spaced relationship to each other, a support arm pivoted about an axis disposed, with respect to said first roll, generally opposite said. second roll, a second support arm carried by said first support arm and extending therefrom at approximately right angles, the unsupported end of Said second arm extending between said first and second rolls, blade securing means carried by the unsupported end of said second arm to secure a blade such that its edge is operatively adjacent the periphery of said first roll, means to precisely adjust the angular position of said first arm with respect to a reference plane passing through the pivot axis thereof, and means to effect precise movement, relative to said first arm, of said second arm along its longitudinal axis, guide means for guiding a running length of yarn consecutive partial wraps around the peripheral surfaces of said first roll and said second rolls at points such that said blade forces said yarn in an acutely angular path a partial distance into the space between the points at which said yarn contacts said peripheral surfaces when said edge of said blade is positioned operatively adjacent the periphery of said first roll, and driving means to drive said rolls in the same direction with respect to each other and to the direction of yarn flow at the point of contact of said yarn with said peripheral surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 270,169 Wilmarth Jan. 2, 1883 2,115,313 Matthew et al Apr. 26, 1938 2,245,874 Robinson June 17, 1941 2,464,502 Hall et a1. Mar. 15, 1949 2,611,923 Hume Sept. 30, 1952 2,639,485 Ambler May 26, 1953 2,673,546 Newton Mar. 30, 1954 2,875,502 Matthews et a1 Mar. 3, 1959 2,921,358 Cox et a1. Jan. 19, 1960 FOREIGN PATENTS 1 ,127 Australia July 15, 1955 558,297 Great Britain Dec. 30, 1943 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,028,654 April 10, 1962 Cyril G. Evans Column 1, line 36, after "problems" insert peculiar column 9, line 50, strike out "the surface thereof", and insert instead it line 51, before "speed" insert surface line 57, before "speed", second occurrence, insert surface same line, after "yarn" insert a period; line 58, strike out "in contact with the surface thereof.

Signed and sealed this 29th day of October 1963.

EDWIN L. REYNOLDS NEST W. SWIDER ztesting Officer Ac ting Commissioner of Patents 

